Blender seems to reset keyframes
Okay, so I downloaded blender 2.8 a few days ago and just tried to open my animation with this version and it seems to be fine. I don't know what went wrong with my 2.79 version, maybe it is some problem with my local installation...

EDIT:

Nevermind, the problem still persists, however, now I am able to get rid of it by pressing STRG+Z sometimes.